Improvement in wrenches



Witz-Le s s e s Inventor.

- Axxys.

N,PTERS, PHDTO-LITHUGRFHER, WASHINGTON. D. C.

duidt I Seite *l este ctie JOHN F. ROBERTSON, OF WARWICK, NEW YORK, -ASSIGNOR OF TWO-THIRDS vHIS RIGHT 'IO JAMES H. HOLLY AND JOHN G. KNA'P, OF SAME PLAGE.l

Leners Patent No. 110,789, dat-ea January s, 1871.

IMPROVEMENT IN WRENCHES.

The Schedule referred to in these Letters Patent and making part of the same.

To all whom it 'may concern B e it known that I, JOHN F. ROBERTSON, of Warwick, in the county of Orange and in Vthe State of New York, have invented certain new and useful Improvements in Wrenches; and do hereby declare that the following is a full, clear, and exact description thereof', reference being had vto the accompanying' drawing making apart of this specilication, in which- Figure 1 is a plan view of my improved wrench; Figure 2 is an edge view of the same with one of the jaws and the sliding head removed;

Figure 3 is a central longitudinal section on thc line x a; of fig. 2; and

Figure 4 is a cross-section on the line z z of fig. 1. Letters of like namcand kind refer to like parts in each of the gures.

My invention is an improvement in adjustable wrenches; and

1t consists principally in the employment of two hinged or pivoted jaws, provided upon their contiguous inner faces with inclined planes' and dovetailed grooves, in combination with a sliding block, substantially as is hereinafter shown.

It also consists in the sliding block or head, operated by and combined with a suitable screw and nut, substantially as is hereinafter set forth.

In the annexed drawing- A and A represent two metal bars, each of which is hinged at one end to or upon the frame or stockB,

so as to have thereon free motion to or from each other. y

As seen in lig. 2, the inner face of each jaw from its outer end downward, for about one inch, is parallel to or withthe general line of said jaw, and provided with serrations, so as to enable nuts or bolt-heads to be firmly grasped, while lfrom said grasping face a to 0r near the pivoted end extends an inclined plane, d', having within its face a dovetail groove, a".

Fitted to or within the space between the inclined planes a is a block, O, having correspondingly inclined contiguous faces, from which extends outward into the dovetailed grooves a", corresponding dovetailed tongues c, by means of which the jaws are held firmly to or against said block.

justed to the necessary distance apart to receive any desired nutor bolt-head.

' In order-to enable the sliding block to be adjusted to and held in position, a screw, D, is secured to its I lower end, and extends downward into the stock B,

. within which a suitable opening is provided for its reception;

A nut, E, fitted to or upon the screw D and working in a recess, b, within the stock B,`enables said screw and the' block to be readily pressed toward or withdrawn from the end of' the jaws.

'A handle, F, fitted to or upon the stock, completes the device, tlleoperation of which has been suiliciently explained.

y rIhe especial advantages possessed by this device are convenience and eiiiciency, combined with sirnplicity of parts, durability, and cheapness.

Having thus fully set forth the nature and merits of my invention,

Vit'nesses Anna FRAN crsco, MAHLON COOPER. 

